Uninterruptible Power Supply Introduction

Uninterruptible Power Supply(UPS) is a device that provides backup AC power to electrical load equipment in an uninterrupted manner to maintain the normal operation of electrical appliances when the power grid is abnormal (such as power outage, undervoltage, interference or surge (inrush current)). Usually, uninterruptible power supplies are used to maintain the uninterrupted operation of critical commercial equipment or precision instruments such as computers (especially servers) or switches to prevent computer data loss, telephone communication network interruption or instrument loss of control.

In North America, the large UPS used in data centers is mainly three-phase 480V, which is different from the three-phase 208V mains power. European data centers use the same three-phase 400V as the mains power.